1. Field of Invention
The present invention relates to entrance seals for securing and sealing pipes penetrating through walls of receptacles to prevent leakage.
2. Description of Related Art
Storage tanks are used for a variety of purposes, but mainly to store bulk fluids such as petroleum products like gasoline or diesel fuel. Storage tanks can be located either above or below ground. Further, storage tanks can have a variety of conduits or pipes that penetrate the wall of the tank. Also, dry tanks are often used to house risers from the bulk fuel tanks and these tanks also have pipes that carry fuel and penetrate the wall of the tank. The orifice in the wall of a tank through which a pipe passes must be sealed for two purposes; first to protect the environment outside the tank from leaking fluids; and second to keep the fluid stored inside the tank free from contaminants. Entrance seals for storage tanks above ground, are fairly simple because the tank is steady and the sealing device is easily accessible. Underground storage tanks present a different set of challenges. Since the tank is underground, the tank is susceptible to any movement or settling of the ground. Consequently, an orifice sealing device must provide some flexibility to allow the pipe to flex as the tank shifts. Additionally, once an entrance seal is installed on an underground tank, access to it without excavating the dirt around the tank is limited.
Therefore, the sealing device for underground storage tank orifices must meet the higher demands of being installed in the underground environment. Conventional storage tank sealing devices; however, have several deficiencies. One such deficiency with conventional devices is that the mounting hardware is exposed to both the corrosive elements internal to the storage tank and the external environment especially if the tank is underground. This exposure will eventually cause the mounting hardware to corrode or rust and require replacement.
Conventional entrance seal also have inadequate and inefficient methods of aligning the mounting hardware. Having a tank wall between the two parts of the sealing device, a worker cannot see the mounting hardware on the other side of the wall. This deficiency increases the installation time required.
Still further, conventional sealing devices do not provide a temporary self-securing mechanism to hold the two parts of the device together while the mounting hardware is installed. This deficiency prevents an installer from having both hands free to complete the installation of the sealing device.
Additionally, conventional orifice sealing devices do not provide an efficient and economical means to seal both the interior and the exterior sides of the orifice as may be required by local and/or national laws.
An additional deficiency of conventional sealing devices is that the devices consist of many parts, such as a sleeve or an insert, a gasket, a ring, a boot and mounting hardware. Or a conventional sealing device may have pieces of different design (i.e. male and female parts), where the internal piece and the external piece are different, requiring installers to be very attentive to which part of the device each worker has; for example: the installer outside the tank must have a piece of the device different but corresponding piece of the device the installer inside the tank will have. This level of attentiveness is often lacking; thus increasing the installation time and decreasing efficiency, because if either of the installers have the wrong piece, one must return to the surface to get the required corresponding piece of the sealing device.
As will be apparent from the description below the present invention will overcome the noted deficiencies of the prior art.